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(Application led Nov. 4, 1898.)

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UNITED STATES PATENT OFFICE.

HARRY P. DAVIS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO TIIE VESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, OF

PENNSYLVANIA.

CIRCUIT-BREAKER.

SPECIFICATION forming part of Letters Patent No. 622,885, dated April 11, 1899.

Application iiled November 4, 1898` Serial No. 695,469. (No model.)

To @ZZ whom t muy concern:

Be it known that I, HARRY P. DAVIS, a citizen of the United States, residing in Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful. Improvement in CircuiteBreakers, (Case No. 794,) of which the following is a speciiication.

My invention relates to devices for interrupting electric circuits; and it has particular reference to devices of this general class that are operated automatically to open the circuits in which they are located upon the passage of a current therethrough that exceeds a predetermined critical amount.

The object of my invention is to provide a circuit-interrupting device that is equally well adapted for direct and alternating current circuits and for any voltage used in commercial service and which is simple and inexpensive in construction and effective in operation.

Modern developments in long distance transmission of electrical energy have been such as to demand special safety devices for opening the transmission-circuits when the currents therein become excessive by reason of either short circuits or overloads. While some of the circuit-interrupting devices heretofore employed have proved reasonably efficient in connection with such comparatively low voltages as have been ordinarily utilized in practice, they are not effective in circuits carrying electromotive forces of several thousand volts,for the reason that it is inexpedient, if not impossible, to provide for a sufficient degree of sepa-ration of the terminals to break the arcs that form between them. Even where fuses have been employed as safety devices devices and to preserve the fuse-terminals from material injury.

In the accompanying drawings, Figure 1 is a side elevation of my circuit-interruptiu g device and a supportingbase therefor. Fig. 2 is a rear elevation of the upper end of one member of the circuit-breaker. Fig. 3 is a horizontal section on line 5c :n of Fig. 1, lookupper end of the movable member of the circuit-breaker.

The structural details of the invention, as shown in the drawings, are as follows:

1 is a suitable supporting base or slab of non-conductin g material, which in a commercial installation will usually be a marble or slate switchboard-panel.

2 and 3 are the main circuit-terminals eX- tending from the front to the rear of the panel I through suitable holes bored therein, as is usual in this class of work. Additional insulation may be provided for the terminals 2 and 3 in cases where the line-voltage is so high as to make it desirable. The linecircuit is joined to the terminals 2 and 3 at the rear of the switchboard by means of suitable connecting devices ll. The front end or head 5 of the terminal 2 is provided with a Wedge-shaped notch 0, opening upward, and the lower terminal 3 is provided with a head 7, having side contaet-surfaces B.

The stationary member 9 of the circuit-in terrupting device comprises a long rod 10, of wood or other suitable non-conducting material, upon the upper end of which is located a fuse-terminal 1l. The lower end of this fuse-terminal is in the form of a tubular socket 12, fitting over the end of the rod l0 and split longitudinally, so that it may be clamped firmly on the rod by means of ears or lugs 13 and bolts or screws 14, passing through the same. Clamped or otherwise fastened to this tubular socket 12 is a U-shaped spring coutact-piece 15, the laterallyprojecting arms of which make frictional contact with the sides of the terminal-head 5 and are connected by means of a suitable pin or stud 16, this pin being of such dimensions and so located that it will enter and rest in the notch 6 of the terminal-head 5. The arms of the contacting upward. Fig. is a side elevation of the IOO piece 15 and the pin 115 together constitute an eye, and since the notched terminal-head 5 is structurally and functionally a hook the stationary member of the circuit-breaker may properly be said to be fastened to the supporting-base 1 by a hook and eye.

The up ier portion of the fuse-terminal 1l is provided with a tubular socket 17, in which is located a cylindrical block 1S of carbon or other substantially infusible material. This block has a central perforation 19 and is clamped in the socket 17 by means of lugs 20 and a bolt or screw 2l, passing therethrough. One of the lugs 2O on the upper portion of the socket 17 is provided with a downwardlyprojecting portion 22, which constitutes the stationary member ot a clamping device 23, the movable member 2t designed to coperate therewith being pivotally mounted upon a stud 25 and having a Literally-projecting arm 2G, to which is fastened a cord 27, and having also a clamping plate or surface 28 in the form of an arc of a circle that is eccentric to the stud The rod 10 is provided with a contact device in the form of a U-shaped spring-contact 2D, clamped thereon in such position longitudinally that the ends of the spring will make frictional contact with the sides S of the main-circuit-terminal head 7 when the pin 1G rests in the bottom of the fork or notch G of the other terminal head 5 and the rod 10 is pressed inward toward the base l. Just below the spring-contact 29 the rod 10 is provided with a bracket 30, having a socket for the rod and being split at one side, so that it may be clamped on the rod by means of the ears or lugs 3l and the bolt 32 extending' there through.

A leaf-spring 33, which may be either single or multiple, is fastened to the front side of the bracket 30 between its projecting arms 30, the spring being of such form that its upwardly-projecting end will tend to press the movable member Si of the circuit-breaker outward, and its lower end will serve as a bu iter or cushion to receive the movable member of the breaker and obviate undue shocks, as well as prevent breaking the apparatus.

The movable member t of the circuitbreaker comprises a hollow rod 35, of wood or other suitable non-conducting material, the lower end of which is surrounded by asuitable metal socket 3G, which is split longitudinally on one side in order that it may be clamped to the rod by means ot bolts, as indicated in Fig. l. This socket is pivoted between the arms SO of the bracket 80, as indicated. The upper end of the rod is provided with a fuse-terminal 37, the lower portion 38 of which is tubular and split along one side, so thatit may iit over the end of the rod and be clamped thereto by means of bolts or screws 39. 'The upper end of the terminal 37 has a tubular socket t0 at right anglesto the socket 38, and in this tubular socket i0 is mounted a longitudinally-perforatcd tubular block 41, of carbon or other substantially infusible material, which is clamped in the socket by means of a screw or bolt 42. The terminal piece 37 is also provided with a bindingscrew The fuse-terminal 37 is connected to the spring-contact 20 by means of a flexible cable it, one end of which is fastened to one side of said spring-contact by means of a suitable connecting device t5. The cable extends up through the longitudinal passage in the rod 35 and is connected at its upper end to the fuse-terminal 37.

A fuse t6, of such material and thickness as may be required for carrying the normal curren t of the system in which the circuit-brcaker is to be used and at the same time so constructed and proportioned that it will be melted er fused by a current that exceeds a predetermined maximum amount, is fastened at one end to the terminal 37 by means of a binding-screw y13 and ext-ends through the longitudinal opening in the block l1 and through the opening 19 in the stationary block 1S, where it is clamped by moving the arm 2G upward, so as to bind its inner end between the stationary piece or abutment and the eccentric face 2S of the movable member of the clamp 23.

The length ot' fuse employed may obviously be anything desired within a considerable range, provided it is strong enough to hold the movable member of the circuit-breaker in position in opposition to the action ot the spring 33.

The operation of the device is the same in principle whether the carbon blocks be held in actual contact or at a considerable distance apart, the only means for holding the movable member of the breaker in any elevated position being' the fuse Ltti and the means for clamping its ends.

The portion of the rod 10 projecting below the lower circuit-terminal 3 is employed in order that the circuit-breaker may be located at such a distance above the iloor that its movable member will not descend low enough to strike the heads of persons who may chance to be beneath when the circuit-breaker opens and at the same time be readily detached and replaced by a person standing upon the iloor when it is desired to insert a new fuse.

The cord 27, attached to the arm 2G of the movable member 24 of the clamp 23, is provided in order that the circuit-breaker may be readily opened by hand from a safe dis-- tance in case the fuse should fail to work or if for any other reason it is desired to interrupt the circuit otherwise than automatically,

It will be understood from the foregoing description that the device will be useful and effective in connection with either direct or alternating current circuits and with any voltage suitable for commercial use.

The device is ad lnirablyadapted to the pu rpose `for which it is intended by reason of its simplicity of construction and the facility with which it may be removed from its norn IOO IIO

mal position and replaced therein and also by reason of the ease and rapidity with which the fuse may be inserted in operative position.

While I have illustrated and described speciic details of construction, I desire it to be understood that the form and dimensions of parts and in general that minor details of construction may be varied within considerable limits without departing from the spirit and scope of my invention, and hence I desire it to be distinctly understood that I do not intend to limit my claims to what is specifically shown and described any further thanlimitations may be imposed by the terms employed or by the state ot' the art.

I claim as my invention-'- l. A circuit-breaker comprising two hingeconnected members, one of which has contact-pieces, in combination with stationary circuit-terminals the heads of which are in position to be engaged by said contact-pieces and with means for so supporting the circuitbreaker as to prevent downward or lateral displacement,`but permitting ready removal when moved upwardly.

2. The combination with a suitablebaseplate having stationary circuit-terminals, of a detachable circuit-interruptin g device having a hook-and-eye connection with one stationary terminal-head and frictional connection with both stationary terminal-heads.

The combination with a supporting-base, ol a circuit-breaker, a stationary7 member having a detachable frictional and hook-and-eye connection with said base, a movable member hinged at one end to the stationary member, and a fuse connecting the ends of the two members opposite the hinge and constituting lthe sole means for supporting the movable member in operative position.

4. A circuit-breaker comprising a stationary member having a substantially infusible terminal-block, a hinged movable member having a substantially infusible terminalblock at its free end, and a fuse normally interposed between the two terminal-blocks.

v5. A circuit-breaker comprising a non-conducting rod having a perforated carbon block at one end, a movable member hinged or pivoted to said rod, and having a perforated carbon block at its free end, a fuse extending through the two carbon blocks and means for clamping its ends to the respective terminals.

6. A circuit-breaker comprising a detachable, but normally-stationary, member havinga carbon terminal-block and an adjacent fuse-clamp, a movable member hinged or pivoted at one end to the stationary member and provided with a carbon terminal-block and a binding or clamping device at its other end, and a fuse interposed between said carbon blocks and fastened in position by the said clamping devices.

7. A circuit-breaker comprising a hinged or pivoted member having a carbon terminalblock and a fuse-clamping device7 in combination with a stationary member having a carbon vterminal-block and a fuse-clamping device, and a cord attached to the movable member of the last-named clamping device for releasing the fuse to open the circuit.

S. The combination with a supporting-base provided with circuit-terminals, of a circuitbreaker stationary member removably attached to and supported by said terminals and provided with a carbon terminal-block, a movable member hinged or pivoted atv one end to said stationary member and provided with a carbon terminal-block at its outer end and a 'Suse interposed between said carbon blocks.

In testimony Whereot` I have hereunto subscribed my name this 2d day of November, 1898.

HARRY P. DAVIS. 

